A representative from Gaga's record label Universal tells Britain's Daily Mirror, "The hackers took a content database dump from www.ladygaga.co.uk and a section of email, first name and last name records were accessed. There were no passwords or financial information taken.
"We take this very seriously and have put in place additional measures to protect personally identifiable information. All those affected have been advised."
Justin Bieber and Amy Winehouse's websites have also recently been targeted by hackers.